View Full Version : r44 weight and balance
peter buzz
7th Nov 2009, 06:59
I note that T.E.Torque is concerned about r44 balance when heavily loaded with low\light fuel. In the fatal accidents he mentions or other similar accidents do we know if the battery was fitted under the instrument panel or engine bay?To my way of thinking Robinson made a serious error putting the battery up the front,from both a balance and cold starting situation. I have owned 2 44s with aft batteries and my present machine is with nose installation.I encourage peoples thoughts on this.
agree that nose mount is a pain when faced with a dead battery, w&b has to be cosidered also when low fuel but heavy pax, all too easy to run out of aft cyclic.
Runway101
7th Nov 2009, 11:21
Which kind of new R44 are equipped with front battery? Is this something from the past or still used on clipper, news, police or IFR trainer versions?
All R44 I or II that ever crossed my way had the battery at the back.
eivissa
7th Nov 2009, 11:39
I agree with RW101,
every 44 I have ever come across had the battery in the back. Clipper I/II made no difference.
What would be a reason to put it up front other than having a very light pilot who usually has to travel with full tanks?
that may be.......................
but at least 2 of us have come across 44's with a battery in the nose, the one i have experience of was built 2002 , raven 1.
firebird_uk
7th Nov 2009, 14:20
Being 234lbs I'm always flirting with the forward CofG limits on the AOC flights I do. Talked to the factory about adding weight to the tail (as Robinson do have a kit for this), but they did not approve it.
The answer of course is to add more fuel, but then the problem changes to an MTOM one.
I guess I shouldn't be eating liquorice allsorts as I write.....:ugh:
Runway101
7th Nov 2009, 14:33
Found some info.
From the Robinson Helicopters Owners Group:
Battery placement is assigned by the factory, and is not a buyer-selectable option. The frame (port side, engine compartment) installation is the preferred location. Before an aircraft is built, a preliminary w&b analysis is calculated, using the various features selected for a specific helicopter. If the analysis predicts that the CG with frame battery is too far aft, the ship is built with an under-seat battery. The target is to have the CG be at 102.5 with full fuel and a pilot.
The R44 Maintenance Manual says the following:
The battery is in a fiberglass container located on the lower left steel tube frame, in the nose under upper console, or in the left-front baggage compartment. Police and E.N.G. versions have the battery suspended from the tailcone.
Apparently battery placement was also a choice you could make many moons ago when you placed the order for the helicopter.
@firebird_uk: Google the "ebook from Tom Venuto" to solve your w&b issues for good.
puntosaurus
8th Nov 2009, 09:14
Being 234lbs I'm always flirting with the forward CofG limits on the AOC flights I do. Talked to the factory about adding weight to the tail (as Robinson do have a kit for this), but they did not approve it.
The answer of course is to add more fuel, but then the problem changes to an MTOM one.
I guess I shouldn't be eating liquorice allsorts as I write.....
Unfortunately there's a gotcha in there too. The sloping nose of the R44 w/b envelope means that as you add fuel, the max fwd c/g comes back at the same rate as you add the fuel. So if you've already put the heaviest pax in the back and you're out of c/g limits, there's nothing you can do with fuel to get back in.
lelebebbel
8th Nov 2009, 10:00
the real gotcha of bringing the CG back by adding fuel is when you - for some reason - lose that fuel, the engine quits, and you now don't have enough aft cyclic to auto..
The Nr Fairy
8th Nov 2009, 10:36
Which is why there's a "CG with full fuel" line on the CG graph. Load within the limits, and you'll be ok.
As ever, disrespect the limits, and become a short-lived test pilot.
Tailboom
10th Nov 2009, 12:25
I fly 2 identialy equiped R44's of almost the same year, the only difference being one has a night kit and has the battery in the rear port engine compartement and the other with no night kit up in the nose. Ive noticed flying with some heavy weight guys that they can easily run out of aft cyclic in the machine with the nose battery. The one heavy guy flys both machines and ive warned him to be aware of the difference it makes.
Hopefully you don't actually mean "run out of aft cyclic"... right?
Even on the absolute forward limit of CofG position, there is happily enough cyclic present to allow for a good flare in auto. The only slight restriction may be gut, rather than stopper - you know who you are!
If you're running out of cyclic then, as they say; you're doing it wrong!
Unhinged
12th Nov 2009, 11:20
R44s have always had batteries in the engine bay.
I have seen four different factory-fitted battery locations on R44s: Nose, LF seat, Engine bay, Tail-boom